Oxyalkylation of the amides of secondary amines



Patented Sept. 15, 1953 OXYALKYLATION' OF THE AMIDES OF SECONDARY AMINES Melvin De Groote, St. Louis, Mo., assignor to Petrolite Corporation, poration of Delaware Wilmington, DeL, a cor- No Drawing. Application October 17, 1951, Serial No. 251,831

Claims. (Cl. 260 404) This invention is concerned with the treatment of certain water-insoluble amides, as hereinafter described, with an alpha-beta alkylene oxide having not over 4 carbon atoms, such as ethylene oxide, so as to render such product water-soluble or emulsifiable by conversion into derivatives, as hereinafter described. The particular amides subjected to such treatment are amides of certain secondary amines. Such amides are characterized by the absence of any reactive hydrogen atom.

It is common practice to treat water-insoluble materials, such as acids, amides, alcohols, phenols, mercaptans and the like, with an alkylene oxide, particularly ethylene oxide, so as to introduce a hydrophile radical. All such compounds are characterized by the fact that they have a reactive hydrogen atom, i. e., a hydrogen atom'attached to oxygen, nitrogen, or sulfur.

I have found that valuable emulsifying agents can be obtained by the oxyalkylation of certain amides, even though such amides do not contain a reactive hydrogen atom. Examples of such amides are the higher fatty acid amides of diethylamine, dipropylamine, dibutylamine, diamylamine, dicyclohexylamine, dihexylamine, dioctylamine, etc. Other examples are the comparable amines, in which the radicals are dissimilar, such as the secondary amines, in which one radical is an ethyl radical and the other propyl, or one is propyl and one is butyl, or one is butyl and one is amyl, etc. For convenience, thesecondary amine may be indicated thus:

in which R represents an alkyl or alicyclic saturated hydrocarbon radical having 2 to carbon atoms. Such secondary amines can be reacted with a monocarboxy acid or its equivalent, so as to yield an amide of the following composition:

N Rl forming. acids.

found, however, that such amide, even though water-insoluble and showing no appreciable s tendency to emulsify prior to treatment with of which is not known at the moment. l ?rean alkylene oxide, can be treated with an alkylene oxide, particularly ethylene oxide, so, as to obtain a water-soluble product which,

seems to be amixture and the exact nature sumably, in part, the product would appear to be the resultant of the reaction, where the ethylene oxide enters at the carbonyl carbon position in a manner indicated thus:

' R =N-C2H4O -R After the introduction of the first mole of alkylene oxide, such as ethylene oxide, it would be immaterial where the next mole entered,.

whether between the carbonyl carbon atom and the adjacent oxygen atom, or between this par- 1 ticular oxygen atom and the adjacent carbon atom, or whether rupture occurred between the nitrogen atom and the carbon atom. Actually, it is believ'edthat the rupture takes'place at a point adjacent to the carbonylcarbon atom.

Thewreacti'ons which actually take place during oxyethylation, may be more complicated than indicated by the previo'u sfsimpler suggestions.

For instance," in my co-pending application,"

Serial No. 59,769, filedNovember 12, 1948, now

Patent No. 2,602,087 I pointed out that a similar reaction takes place when one oxyalkylates an ester of an aminoalcohol of the following composition:

R A I in which R is a member selected from the class of alkyl and saturated alicyclic hydrocarbon radicals having at least 2 and not over 10 carbon atoms; R10 is the divalent radical in which R10 is a member selectedafrom the class consisting of ethylene radicals, propylene radicals, butylene radicals, hydroxypropylene, radicals and hydroxybutylene radicals, and n-is a number varying from, 1 to 3; RzCO is the acyl radical'of a monocarboxy,detergent-forming acid having 8to 20 carbon atoms. 1 i a If in the instant case all that happened wasthatv the first. mole: of :the .alkylene oxide, such,

as ethylene oxide, entered in the manner suggested previously by the following formula =N-C zHAO C R then the initial product of reaction would be the same identical product as described in the aforementioned co-pending application. Stated another way, in my co-pending application I might start, for example, with "the oleyl :or

stearyl ester of dibutylethanolamine. In the in-' stant case I might start with dibutyl oleylamide or stearamide; employing one mole of ethylene oxide there would be introduced the divalent ethanol radical between what was formerly the amide nitrogen atom and the .acyl radical. 21f

this actually took place, then the resultant would be the same as the intial reactant in the aforementioned co-pending application. Actually, the products obtained by oxyalkylating these two comparable raw materials, yield derivatives or mixtures of derivatives which are distinctly dissimilar.

'Consider'ing for a moment, however, that such ester linkage could be formed, even so, further oxyalkylation seems to indicate greater comple'xity. For instance, there may be a rupture involving one fragment at the carbonyl carbon atom, and another fragment at the adjoining oxygen atom. This *is shown in the following manner:

or it might be possible, of course, that another mole of ethylene oxide furnishes a connective divalent radical, as indicated in the following:

a e c As stated, it do not knoii n the composition completely and regard it as a mixture and "it probably represents, at least part, other reaction products in addition to "those which have been briefly indicated. Regardless of the composition, it zis to "be noted that iny irrvention is directed to thesdbstaritial fact that I have found acid number.

that these particular amides, free from reactive hydrogen atoms, are susceptible to oxyalkylation, and such products are of, utility, particularly for use as emulsifiers for oil-in-water emulsions.

' Previous reference has been made to the higher :fatty acids which represent my preferred reactants. The higher fatty acids include caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid, .stearic acid, as well as hydroxy- ,stearic acid, dihydroxystearic acid, trihydroxystearic acid, etc., as well as the unsaturated higher :catty acids, such as oleic acid, linoleic acid, linolenic acid, ricinoleic acid, etc. Previous reference has been made to the use of naphthenic acids, and particularly naphthenic acids of commerce in the two grades ordinarily available, to wit, 220-230 acid number and 230-240 The invention can be illustrated by such examples as the oleic acid ester, ricinolei'c acid 21681361, or linoleic acid ester of diethylethanolamine or 'di'butylethanol-amine. The following examples illustrate the oxyal kylation procedure, particularly oxyethylation, which is comparatively simple and more or less conventional, and :is employed in reacting compounds which happen to have a reactive hydrogen atom.

There may be an anomaly in the .fact that reference has been made to the absence of reactive hydrogen atoms in the ester which is subjected to oxyalkylation, and at the same time esters [of ricinoleic acid, hydroxystearic acid, :and the like have been included. Ethylene oxide reacts with primary :alcohols. Apparently, however, under ordinary conditions of reaction for even under the more drastic conditions of --reaction herein described, ethylene oxide or the other alkylene oxides .do not react with "the secondary alcoholic radicalwhich is part :of an :acy-l radical, asin the case of ric'inoleic :acid, hydroxystearic iacid, etc. In fact, if ricinoleic acid or ethyl .nicinoleate :is subjected to Dxyalkylation, particularly 0x5"- ethylation, .one does not :obtain a compound ,in which the alcoholic hydroxyl of the ricinoleyl radical has been attacked.

i'alhesame applies in norm ticm with the .00mpounds herein described, if one happens [to cmploy an ester 'in "which "the -ricinoleyl 101 similar group is present. if the :final product is $31.1)- jected to :saponifrcation then acidified and extracted so as to recover the fiatty acid -.as such, examination of the fatty acid reveals that it is the unaltered original iatty acid and :not the fatty acid of the following type:

wherein R10 represent a divalent alkylene oxide radical and 'HORc'CQOiH represents .ricinoleic acid, mydroxystearic acid, or the like.

The selected-amide is placedin-a stirring autoclave and subjected to t'reatment with ethylene oxide or one oi the other similar :alkylene oxides as noted. Since these amides are not basic, it is desirable to add an alkaline catalyst, in order to effect oxyalkylation. Any of the usual alkaline catalysts employed in oxyalkylation may be used, :for example, caustic soda, caustic ipptash, soap, carbonates, so dium anethylate, aetc. it :has been found ithat'2% of so'diumimethylate, based on'the weight "of theramidafis satisfactory. 5311c mixture of "the amide andrsodium imethylate was placed in :a stirring autoclave and .ethylene i oxide added batch-wise. Generaliy speaking, :the time required for dihe addition "Of sgrams of .ethyh ener'oxide to .400 or 500 grams of the amide, is about two hours, operating at a temperature of about 150 to 175 C., and a gauge pressure of up to 200 pounds per square inch. As the re-, action becomes complete, the pressure drops to a very low value. In some instances, the re- The final product separated into two layers. both of which are water-soluble and serve as emulsifying agents, and both-of which are $01- u'ble in the diethylether of diethyleneglycol. Iiv

action mass is nonhomogeneous andit has been desired, the mixture can be stirred and used found desirable to add some of the diethylether while being agitated, so as to get adequate porof diethyleneglycol in order to promote homotrons of both layers, or either layer can be emgeneity. The procedure is illustrated by the 1'01- pl y d separ t ly. lowing examples: Example 4 Example 1 i Grams Grams Diethylstearamide 320.2 Dlbutyloleylamide methylate 6 0 sodium methylate 8 Ethylene oxide (6 portions of 100 grams Ethylene oxide (5 portions of 150 g. each) 750 h o x eac 6 0 Temper Pres Tem er- Pres- Time aglge, Time atlll e, surep. C. p. s. i. gig":-

gg Mhour-.. 160 142 Non-viscous, water-emulsiflable liq- 2:501: 115 Emulsifiable. 41mm 160 172 gg 15s 1 hours: I 155 190 Do: j 175 2g Ghours... 160 135 Nonvtiscous, wateg-emullsitfiable liq- I lll ecommg W2. er-so H e. 155 35 gg g gg gg gi gfggg g fig igi fihours-.- 160 140 Non-viscous, water-soluble liquid.

flalblie. Aiddeld 1diethylether of di- 2 9=55 10 1 at yeneg 00mm The final product separated into two layers. 10:00.... 150 185 but the lower layer was a rather-viscous liquid 1 215.... 170 E ulslfl bl 0t sol bl 3930"," 100 11 m a u e and the upper layer was somewhat thinner. If 3:35"... 150 170 desired the mixture can be stirred and used 4:10-... 170 20 Emulsitiable non-homogeneous waxlike, grainy black product. 30 while being agitated, so as to get adequate porigg trons of both layers, or either layer can be em 105251111 160 125 ployed separately. 11:00.... 170 20 Separates into 2 layers but is homogeneous temporarily after being Exa pl 5 mixed together. Both layers are soluble and emulsiflable and are surq Grams ro aotive. Tli o a ppe arange of the Dicyclohexyllauramide 360 S01 01189111113 on $811105 WBXY. Sodium methylate 7 Ethylene oxide ,(5. portions of 100 grams wampl 2 each) 500 Grams 4 0 Dibutyl lauramide 299 Temper Prey Sodium methylate 6 Time agure, sure, Ethylene oxide (4 portions of 100 grams I each) 400 2h0urs. 165 175 er 123 i Tom er- Presours- 70 Time l, 5 hours 160 152 0, ,1, Do.-. 160 145 N on-viscous, water-soluble liquid.

3 hours-.. 160 160 Water-emulslflable liquid.

Do--- 165 165 Non-viscous, water-emulsitiable when propylene Oxide Was used, the nt 3% ho rs 155 180 q g of alkylene oxide was increased one-third over 3 160 155 the values where ethylene oxide was employed, i. e., 200 grams of propylene oxide were used to The final product separated into two layers, both of which are water-soluble and serve as emulsifying agents, and both of which are soluble in the diethylether of diethyleneglycol. If desired, the mixture can be stirred and used while being agitated, so as to get adequate portions of both layers, or either layer can be employed separately.

Example 3 Grams Dibutyl stearamide 284 Sodium methylate 5.5

Ethylene oxide (3 portions or 100 gr.

each) 300 Temper- Pres- Iime ature, sure,

C. p. s. i.

3 hours..- 165 142 wgiisgr-emulsifiable non-viscous liq- 736 hours. 160 180 Db. 7 hours... 160 170 Water-emulsifiable non-viscous oil.-

replace grams of ethylene oxide. Propylene oxide does not give nearly as satisfactory a product, due to lesser water-solubility. It is most advantageous to use either ethylene oxide alone, or a mixture of ethylene oxide and propylene oxide, particularly using propylene oxide in the early batches and ethylene oxide in the later batches. When propylene oxide is used, the pressure may be less, due to the lower vapor tension of propylene oxide, but its reactivity is lower and the time required may be two or three times that required with ethylene oxide. Sometimes slightly higher temperatures must be employed with propylene oxide. For various reasons, the most desirable, the cheapest and the most effective alkylene oxide is ethylene oxide. The objection to glycide is its expense and the extreme care with which it must be handled.

Some of the amides employed as raw materials, for instance, the higher fatty acid amides, such as dibutyl-oleylamide, diethylstearamide, dibutylstearamide, diethyllauramide can be distilled and are readily available as pale amber or redl 7 dish amber liquids which darken readily in p the presence of air,'or sometimes due'to the action of light alone. The products obtained by oxyal kylat'ion vary from greyish brown pasty and waxy solids, at ordinary roomtemperature, to others product homogeneous.

It is to be noted that the amides, prior to oxyal-kylation, are insoluble. Since the-amides are not particularly alkaline, this is apt to be true, even if the water is slightly acidulated.

The products, as prepared, will make a solution with warm distilled water, using 1 to 5 parts of the oxyalkylated derivative mixture and 95' to 99 parts of warm distilled water (temperature 30 to 50 C.) to give a permanent sol or solution. In some instances, this solution is practically clear and transparent. This test applies whether the product is used as such, or whether it has been mixed with xylene and the diethylether ofdiethyleneglycol, as previously pointed out. Such mixtures are by weight. Y

This application is in part a continuation of my application Serial No. 59,770, filed November 12, 1948, now abandoned.

I claim:

1. The process of rendering water-insoluble amides water-dispersible by reaction with an alkylene oxide; said water-insoluble amide, prior to oxyalkylation, being of the following formula:

which are reactivetowards low molal alkylene oxides; said reaction being carried out-,by sub.- jecting the amide to the action of the alkylene oxide under oxyalkylating conditions of temperature and pressure, the alkylene oxide having at least 2 and not more than 4 carbon atoms se lected from the class consisting of ethylene ox-y ide, propyleneoxide, butylene oxide, glycide and methylglycide, andbeing at least suflicient to render the water-insoluble amide water-dispersible to a degree sufficient to give a permanent solution in'a mixture containing 1% to 5% of the oxyalkylated derivative mixture'and to 99% of warm distilled Water.

2. The process of claim 1, wherein R. 1s alkyl.

3. The process of claim 1, whereinR, is alkyl and R100 is the acyl radical of a higher fatty acid.

4. The process of claim 1, wherein R is alkylv and R100 is the acyl radical of an unsaturated higher fatty acid.

5. The process of claim Number Name Date 1,924,698 Neelmeier'et al Aug. 29, 1933 1,970,573 Schoeller et al Aug. 21, 1934 1,985,424 Piggott Dec. 25., 1934 2,002,613 Orthner et a1. H May 28, 1935'.

1, wherein R, is alkyl, R100 isthe acyl radical of an unsaturated higher 

1. THE PROCESS OF RENDERING WATER-INSOLUBLE AMIDES WATER-DISPERSIBLE BY REACTION WITH AN ALKYLENE OXIDE; SAID WATER-INSOLUBLE AMIDE, PRIOR TO OXYALKYLATION, BEING OF THE FOLLOWING FORMULA: 